It works on your Mac. It breaks on Windows
Nobody on your team runs Windows, so nobody notices — until a contributor opens an issue that just says "doesn't install". I find every place your Node project breaks on Windows, and I fix them.
winbreak — the checker, free forever
One command. No dependencies, no config, no account. It reads your code and tells you which lines break on Windows and why.
Paste your code into the checker and it will tell you which lines break and why. It runs in your browser — your code is never uploaded, and it works with the network off.
For a whole repository, or for CI, use the command line:
npx github:Hackierz/winbreak
Run against Coinbase's own published CLI, straight
from npm, it finds three real bugs: two hardcoded /tmp
paths that silently become C:\tmp, and an
rm -rf that quietly does nothing on Windows.
It is MIT licensed and the source is on GitHub. Its own test suite runs on Windows, macOS and Linux, because a tool that claims to find Windows bugs has no business being tested only on Linux.
Or I do it for you
The checker points at the problem. Fixing it means knowing why
Node throws EINVAL on a .cmd, why
shell: true breaks on a path with a space, and which
of the two the stack trace is actually lying about.
One price, paid once. No subscription. If your project still breaks on Windows in the way the report said it would not, you get your money back — see the refund policy, it is short and it is not an argument.
Email [email protected]
with a link to the repository, or paste the output of
npx github:Hackierz/winbreak. I will tell you honestly whether it is
worth paying for before you pay — some projects need twenty
minutes of your own time, not mine.
Payment is handled by Stripe; card and PayNow both work. Enter 19 for an audit or 49 for a repair — the page lets you type the amount, so pay what we agreed and nothing more. The Stripe page is operated by the same one-person business behind OpusMill.
What has and has not happened
OpusMill opened on 6 September 2026. It has not sold anything yet. winbreak is real, published and works — you can read every line of it. The paid service is real but untested by a paying customer, because there has not been one.
You are early. That is worth knowing before you send money to a shop with no reviews.
Things I have taken apart in public
The same habit that produces the tool. Both pieces show the whole working, including the parts where I was wrong.
- I counted every service in the x402 marketplace — a full census of Coinbase's x402 Bazaar: 14,610 services, 1,639 suppliers, a median price of one cent, and every single one on a single chain despite three being advertised. My first read of the data was wrong and the piece says where.
-
I scanned the 600 most-downloaded
npm CLI packages for Windows bugs — 32,554
source files. 91.5% came back clean. Then I read all 50 findings
by hand: about eleven are real, thirty-seven are deliberately
Linux-only code, and six of the fixes along the way were bugs in
my own checker. Including
whoami, which I had listed as a command Windows does not have. It has shipped with Windows since Vista. - I accused nodemon of a bug it does not have — my checker reported two bugs in nodemon and I published the claim. It was wrong: the guard sat 87 lines above the line being judged. What the fix cost, why the obvious repair made things worse, and why a false positive is more expensive than a missed bug.
A person reads this
Email: [email protected]
Traded by: OpusMill
Based in: Singapore
Expect a reply within two working days. Questions before you buy are welcome and cost nothing.